The present invention relates to a fusion welding device of works for joining by fusion welding the works such as resin frame members which form a resin frame of a resin sash, a resin frame of a resin screen, etc., and an assembling apparatus of the resin frame for assembling the resin frame such as a resin window frame, a resin screen frame, etc. using the fusion welding device.
A window frame is assembled by connecting four pieces of frame members in a shape of bar (an upper frame, a lower frame, and vertical frames at right and left sides) into a rectangular shape. A sash is formed by fitting a screen to this window frame.
A screen frame is assembled by connecting four pieces of frame members in a shape of bar (an upper frame, a lower frame, and vertical frames at right and left sides) into a rectangular shape.
A screen is formed by fitting a glass panel or the like to this screen frame.
As the aforesaid window frame and screen frame, a metal frame employing frame members formed of metal (hereinafter referred to as metal frame members), and a resin frame employing frame members formed of resin (hereinafter referred to as resin frame members) have been known.
In case of the aforesaid metal frame, the frame is assembled by connecting end portions of the metal frame members to each other with small screws or the like.
On the other hand, in case of the aforesaid resin frame, the frame is assembled by cutting end portions of the resin frame members at 45 degree, and joining them by fusion welding.
As described above, in order to join the end portions of the resin frame members by fusion welding, the end portions to be joined are fused with heat of a heater, as a first step, and then, the end portions are joined to each other by abutting and pressing their end faces which have been fused to each other, and thereafter, cooled, whereby the fused parts are hardened to make an integral member.
In case where the resin frame members are joined by fusion welding as described above, the end portions of the resin frame members are pressed when they are fused by the heater, or when the fused end portions are joined. Consequently, the end portions protrude outward, and fins may occur.
Generally, these fins are removed by cutting with a cutter or the like after the end portions have been joined.
Such being the circumstances, a process for removing the fins is required, and therefore, assembling cost for the resin frame is increased.
Moreover, those regions where the fins have been removed by cutting may be sometimes different in color from other regions, and hence, an outer appearance is deteriorated.
In view of the above, a related-art fusion welding device for preventing occurrence of fins in the regions which have been joined by fusion welding (a heat-fusion joining and working device) is disclosed in JP-A-2001-150552.
This related-art fusion welding device includes a pair of work grasping units which grasp the work to move it between a waiting position and a heat fusing position, and a heater unit. A mold assembly of the work grasping unit includes a fixed side mold assembly and a movable side mold assembly. The movable side mold assembly is movable toward the fixed side mold assembly when pressed at a time of joining. Because end portions of the work are fused and joined by fusion welding in a state where the end portions have entered in the movable side mold assembly, the end portions will not protrude outward, and occurrence of fins can be prevented.
In the above described related-art fusion welding device, when the end portions of the works are fused and joined by fusion welding, fusion and fusion welding are carried out, by moving the movable side mold assembly toward the fixed side mold assembly. However, because the movable side mold assembly is supported by a resilient member such as a spring, and the mold assembly is closed with a spring force, there is such anxiety that the mold may be opened with pressure of fins which apt to protrude outward, and the fins may occur.
Moreover, in order to press the end portions of the two works, the works are moved in respective longitudinal directions thereof together with the respective work grasping units (the mold assembly) in a state where the end portions of the works are grasped by the respective work grasping units, whereby the end portions come close to each other to be pressed.
For this reason, in order to assemble a frame, fusion welding operation must be conducted at every corner of the frame, and hence, assembling work of the frame requires a considerable time.
For example, in case where the frame in a rectangular shape is assembled, fusion welding operations must be sequentially conducted four times at the four corners of the frame, and the assembling work requires a lot of time.